Flexor Hallucis Longus decompression under ultrasound guidance: A cadaver study.

INTRODUCTION: The Flexor Hallucis Longus (FHL) is a muscle that can be subject to multiple impingements caused by exaggerated plantar flexion in athletes. The most common impingement is due to inflammation of the tendon at the retrotalar pulley. The constraints exerted on the FHL are responsible for a pathology called functional Hallux Limitus. Surgical treatment consists of tenolysis of the FHL arthroscopically or via open surgery, by opening the pulley. The objective of this study was to evaluate the risk of lesions of the neurovascular pedicle and the posterior tibial tendon after tenolysis of the Flexor Hallucis Longus under ultrasound guidance. HYPOTHESIS: The hypothesis of this study is that tenolysis of the Flexor Hallucis Longus could proceed under ultrasound guidance without associated tendon lesions or neurovascular lesions. MATERIAL AND METHODS: Thirteen cadaveric specimens were studied, resulting in an analysis of 26 feet. Following identification of the Flexor Hallucis Longus, tenolysis with a 19-gauge needle under ultrasound guidance was performed by an orthopedic specialist after hydrodissection to push back the posterior tibial pedicle. The dissection of the cadavers made it possible to verify the positioning of the posterior tibial pedicle, the FHL tendon and the opening of the retrotalar pulley. RESULTS: Five cadaveric subjects, 10 cases, underwent a complete opening of the retrotalar pulley under ultrasound guidance. In 16 cases, the opening was partial, with a section of the pulley of 65.87±18%. The cases of partial openings showed no neurovascular or tendinous lesions. The 10 cases of complete opening resulted in 5 lesions of the tibial nerve, 4 vascular lesions: 1 venous and 3 arterial, and 6 lesions of the FHL tendon. CONCLUSION: Tenolysis of the Flexor Hallucis Longus under ultrasound guidance at the level of its retrotalar pulley was systematically associated with neurovascular lesions in the event of complete release of the pulley by the method studied, unlike a partial release where no lesion was found. LEVEL OF EVIDENCE: III; case-control study.

Treatment of Flexible Lesser Toe Deformities.

Lesser toe deformities are among the most common complaints presented to foot and ankle specialists. These deformities present in variable ways, which makes surgical decision making complex. For every type of deformity, there could be a combination of soft tissues and bony procedures, chosen according to the surgeon's preferences. This article first describes modern classification of lesser toe deformities, and then presents the different treatments and procedures available for those flexible deformities. In addition, this article proposes an algorithm based on clinical/radiological evaluation and step-by-step surgical decision making.